Rosenberg says the Federal Reserve has "completely altered" the relationship between stocks and bonds by promoting low interest rates. Even though the economy and corporate earnings are weak, the interest rate used to discount corporate future earnings streams is negative, which raises earning expectations.

"The fact that the S&P dividend yield is triple the yield in the belly of the Treasury curve has also added to the allure of equities, or at least those that have compelling dividend yield, growth and coverage characteristics," Rosenberg wrote.

Investors sticking to cash and super-safe investments should realize that interest income is in a bear market and dividend income is in a "massive bull market," Cullen Roche, founder of Orcam Financial Group, quoted Rosenberg as stating in an article for Pragmatic Capitalism.

By buying large amounts of bonds, the Fed has pushed the five-year Treasury yield down to 60 basis points, or just 0.6 percent, Rosenberg noted. By comparison, the dividend yield in the stock market is approaching 2.3 percent. That's a difference the markets haven't seen since 1958.